In Bangladesh, as in many other low-lying countries, river flooding often leaves large swaths of land under

Question:

In Bangladesh, as in many other low-lying countries, river flooding often leaves large swaths of land under water for substantial portions of the year. By building embankments on the side of the river, governments can extend the growing season, allowing several seasons of crops. The result is a wealth increase for people living in affected rural areas. In a recent paper, several economists traced through some unusual consequences of increasing the wealth of rural populations by creating embankments. In Bangladesh, marriages require dowries, paid by the bride’s family to the groom. For poor families, raising these dowries can be difficult and it is not easy to marry now and promise a dowry-by-installment later on. Making people live up to their promises and pay debts is no easier in Bangladesh than it is elsewhere in the world! The result? In hard times and among the poorer families, people in Bangladesh often marry cousins; promises within an extended family are more easily enforced and wealth sharing inside families is also more common.

Now let us think about what happens when the government builds a flood embankment, allowing farmers on one side of the embankment to till the land over most of the year, while those on the other side are faced with six-month flooding.

Farmers on the flooded side of the river continue to use marriage within the extended family as a strategy to essentially provide dowries on credit. For those farmers on the more stable side of the river, cousin marriages fell quite substantially. Marriage of cousins can have health risks, thus investments in rural infrastructure can have unforeseen positive effects in an area.